Exhaust manifold



FIG. 1 is a front, top and right side perspective view of an exhaust manifold embodying my design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for an exhaust manifold, as shown and described. 